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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 8c8428a576f632745306e288b629e30d420c0f5a / . / cpu / leon2 / start.S
blob: 937ea1ed7741240eac29a4d9717c7f2ebd595cf9 [file] [log] [blame]
Daniel Hellstromb3309902008-03-28 10:00:33 +0100[diff] [blame]1/* This is where the SPARC/LEON3 starts
2 * Copyright (C) 2007,
3 * Daniel Hellstrom, daniel@gaisler.com
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23
24#include <config.h>
25#include <asm/asmmacro.h>
26#include <asm/winmacro.h>
27#include <asm/psr.h>
28#include <asm/stack.h>
29#include <asm/leon.h>
30#include <version.h>
31
32/* Entry for traps which jump to a programmer-specified trap handler. */
33#define TRAPR(H) \
34 wr %g0, 0xfe0, %psr; \
35 mov %g0, %tbr; \
36 ba (H); \
37 mov %g0, %wim;
38
39#define TRAP(H) \
40 mov %psr, %l0; \
41 ba (H); \
42 nop; nop;
43
44#define TRAPI(ilevel) \
45 mov ilevel, %l7; \
46 mov %psr, %l0; \
47 b _irq_entry; \
48 mov %wim, %l3
49
50/* Unexcpected trap will halt the processor by forcing it to error state */
51#undef BAD_TRAP
52#define BAD_TRAP ta 0; nop; nop; nop;
53
54/* Software trap. Treat as BAD_TRAP for the time being... */
55#define SOFT_TRAP TRAP(_hwerr)
56
57#define PSR_INIT 0x1FC0 /* Disable traps, set s and ps */
58#define WIM_INIT 2
59
60/* All traps low-level code here must end with this macro. */
61#define RESTORE_ALL b ret_trap_entry; clr %l6;
62
63#define WRITE_PAUSE nop;nop;nop
64
65WINDOWSIZE = (16 * 4)
66ARGPUSHSIZE = (6 * 4)
67ARGPUSH = (WINDOWSIZE + 4)
68MINFRAME = (WINDOWSIZE + ARGPUSHSIZE + 4)
69
70/* Number of register windows */
71#ifndef CFG_SPARC_NWINDOWS
72#error Must define number of SPARC register windows, default is 8
73#endif
74
75#define STACK_ALIGN 8
76#define SA(X) (((X)+(STACK_ALIGN-1)) & ~(STACK_ALIGN-1))
77
78 .section ".start", "ax"
79 .globl _start, start, _trap_table
80 .globl _irq_entry, nmi_trap
81 .globl _reset_reloc
82
83/* at address 0
84 * Hardware traps
85 */
86start:
87_start:
88_trap_table:
89 TRAPR(_hardreset); ! 00 reset trap
90 BAD_TRAP; ! 01 instruction_access_exception
91 BAD_TRAP; ! 02 illegal_instruction
92 BAD_TRAP; ! 03 priveleged_instruction
93 BAD_TRAP; ! 04 fp_disabled
94 TRAP(_window_overflow); ! 05 window_overflow
95 TRAP(_window_underflow); ! 06 window_underflow
96 BAD_TRAP; ! 07 Memory Address Not Aligned
97 BAD_TRAP; ! 08 Floating Point Exception
98 BAD_TRAP; ! 09 Data Miss Exception
99 BAD_TRAP; ! 0a Tagged Instruction Ovrflw
100 BAD_TRAP; ! 0b Watchpoint Detected
101 BAD_TRAP; ! 0c
102 BAD_TRAP; ! 0d
103 BAD_TRAP; ! 0e
104 BAD_TRAP; ! 0f
105 BAD_TRAP; ! 10
106 TRAPI(1); ! 11 IRQ level 1
107 TRAPI(2); ! 12 IRQ level 2
108 TRAPI(3); ! 13 IRQ level 3
109 TRAPI(4); ! 14 IRQ level 4
110 TRAPI(5); ! 15 IRQ level 5
111 TRAPI(6); ! 16 IRQ level 6
112 TRAPI(7); ! 17 IRQ level 7
113 TRAPI(8); ! 18 IRQ level 8
114 TRAPI(9); ! 19 IRQ level 9
115 TRAPI(10); ! 1a IRQ level 10
116 TRAPI(11); ! 1b IRQ level 11
117 TRAPI(12); ! 1c IRQ level 12
118 TRAPI(13); ! 1d IRQ level 13
119 TRAPI(14); ! 1e IRQ level 14
120 TRAP(_nmi_trap); ! 1f IRQ level 15 /
121 ! NMI (non maskable interrupt)
122 BAD_TRAP; ! 20 r_register_access_error
123 BAD_TRAP; ! 21 instruction access error
124 BAD_TRAP; ! 22
125 BAD_TRAP; ! 23
126 BAD_TRAP; ! 24 co-processor disabled
127 BAD_TRAP; ! 25 uniplemented FLUSH
128 BAD_TRAP; ! 26
129 BAD_TRAP; ! 27
130 BAD_TRAP; ! 28 co-processor exception
131 BAD_TRAP; ! 29 data access error
132 BAD_TRAP; ! 2a division by zero
133 BAD_TRAP; ! 2b data store error
134 BAD_TRAP; ! 2c data access MMU miss
135 BAD_TRAP; ! 2d
136 BAD_TRAP; ! 2e
137 BAD_TRAP; ! 2f
138 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 30-33
139 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 34-37
140 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 38-3b
141 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 3c-3f
142 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 40-43
143 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 44-47
144 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 48-4b
145 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 4c-4f
146 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 50-53
147 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 54-57
148 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 58-5b
149 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 5c-5f
150
151 /* implementaion dependent */
152 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 60-63
153 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 64-67
154 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 68-6b
155 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 6c-6f
156 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 70-73
157 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 74-77
158 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 78-7b
159 BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 7c-7f
160
161 /* Software traps, not handled */
162 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 80-83
163 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 84-87
164 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 88-8b
165 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 8c-8f
166 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 90-93
167 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 94-97
168 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 98-9b
169 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 9c-9f
170 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! a0-a3
171 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! a4-a7
172 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! a8-ab
173 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! ac-af
174 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! b0-b3
175 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! b4-b7
176 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! b8-bb
177 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! bc-bf
178 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! c0-c3
179 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! c4-c7
180 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! c8-cb
181 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! cc-cf
182 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! d0-d3
183 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! d4-d7
184 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! d8-db
185 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! dc-df
186 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! e0-e3
187 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! e4-e7
188 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! e8-eb
189 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! ec-ef
190 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! f0-f3
191 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! f4-f7
192 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! f8-fb
193 SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! fc-ff
194/*
195 * Version string
196 */
197
198 .data
199 .globl version_string
200version_string:
201 .ascii U_BOOT_VERSION
202 .ascii " (", __DATE__, " - ", __TIME__, ")"
203 .ascii CONFIG_IDENT_STRING, "\0"
204
205 .section ".text"
206 .align 4
207
208_hardreset:
2091000:
210 flush
211 nop
212 nop
213 nop
214
215 /* Init Cache */
216 set (LEON2_PREGS+LEON_REG_CACHECTRL_OFFSET), %g1
217 set 0x0081000f, %g2
218 st %g2, [%g1]
219
220 mov %g0, %y
221 clr %g1
222 clr %g2
223 clr %g3
224 clr %g4
225 clr %g5
226 clr %g6
227 clr %g7
228
229 mov %asr17, %g3
230 and %g3, 0x1f, %g3
231clear_window:
232 mov %g0, %l0
233 mov %g0, %l1
234 mov %g0, %l2
235 mov %g0, %l3
236 mov %g0, %l4
237 mov %g0, %l5
238 mov %g0, %l6
239 mov %g0, %l7
240 mov %g0, %o0
241 mov %g0, %o1
242 mov %g0, %o2
243 mov %g0, %o3
244 mov %g0, %o4
245 mov %g0, %o5
246 mov %g0, %o6
247 mov %g0, %o7
248 subcc %g3, 1, %g3
249 bge clear_window
250 save
251
252leon2_init:
253 /* LEON2 Register Base in g1 */
254 set LEON2_PREGS, %g1
255
256leon2_init_cache:
257 /* Set Cache control register */
258 set 0x1000f, %g2
259 st %g2, [%g1 + 0x14]
260
261leon2_init_clear:
262
263 /* Clear LEON2 registers */
264 st %g0, [%g1 + LEON2_ECTRL]
265 st %g0, [%g1 + LEON2_IMASK]
266 st %g0, [%g1 + LEON2_IPEND]
267 st %g0, [%g1 + LEON2_IFORCE]
268 st %g0, [%g1 + LEON2_ICLEAR]
269 st %g0, [%g1 + LEON2_IOREG]
270 st %g0, [%g1 + LEON2_IODIR]
271 st %g0, [%g1 + LEON2_IOICONF]
272 st %g0, [%g1 + LEON2_UCTRL0]
273 st %g0, [%g1 + LEON2_UCTRL1]
274
275leon2_init_ioport:
276 /* I/O port initialization */
277 set 0xaa00, %g2
278 st %g2, [%g1 + LEON2_IOREG]
279
280leon2_init_mctrl:
281
282 /* memory config register 1 */
283 set CFG_GRLIB_MEMCFG1, %g2
284 ld [%g1], %g3 !
285 and %g3, 0x300, %g3
286 or %g2, %g3, %g2
287 st %g2, [%g1 + LEON2_MCFG1]
288 set CFG_GRLIB_MEMCFG2, %g2 ! Load memory config register 2
289#if !( defined(TSIM) || !defined(BZIMAGE))
290 st %g2, [%g1 + LEON2_MCFG2] ! only for prom version, else done by "dumon -i"
291#endif
292 set CFG_GRLIB_MEMCFG3, %g2 ! Init FT register
293 st %g2, [%g1 + LEON2_ECTRL]
294 ld [%g1 + LEON2_ECTRL], %g2
295 srl %g2, 30, %g2
296 andcc %g2, 3, %g6
297 bne,a leon2_init_wim
298 mov %g0, %asr16 ! clear err_reg
299
300leon2_init_wim:
301 set WIM_INIT, %g3
302 mov %g3, %wim
303
304leon2_init_psr:
305 set 0x1000, %g3
306 mov %psr, %g2
307 wr %g2, %g3, %psr
308 nop
309 nop
310 nop
311
312leon2_init_stackp:
313 set CFG_INIT_SP_OFFSET, %fp
314 andn %fp, 0x0f, %fp
315 sub %fp, 64, %sp
316
317cpu_init_unreloc:
318 call cpu_init_f
319 nop
320
321/* un relocated start address of monitor */
322#define TEXT_START _text
323
324/* un relocated end address of monitor */
325#define DATA_END __init_end
326
327reloc:
328 set TEXT_START,%g2
329 set DATA_END,%g3
330 set CFG_RELOC_MONITOR_BASE,%g4
331reloc_loop:
332 ldd [%g2],%l0
333 ldd [%g2+8],%l2
334 std %l0,[%g4]
335 std %l2,[%g4+8]
336 inc 16,%g2
337 subcc %g3,%g2,%g0
338 bne reloc_loop
339 inc 16,%g4
340
341 clr %l0
342 clr %l1
343 clr %l2
344 clr %l3
345 clr %g2
346
347/* register g4 contain address to start
348 * This means that BSS must be directly after data and code segments
349 *
350 * g3 is length of bss = (__bss_end-__bss_start)
351 *
352 */
353
354clr_bss:
355/* clear bss area (the relocated) */
356 set __bss_start,%g2
357 set __bss_end,%g3
358 sub %g3,%g2,%g3
359 add %g3,%g4,%g3
360 clr %g1 /* std %g0 uses g0 and g1 */
361/* clearing 16byte a time ==> linker script need to align to 16 byte offset */
362clr_bss_16:
363 std %g0,[%g4]
364 std %g0,[%g4+8]
365 inc 16,%g4
366 cmp %g3,%g4
367 bne clr_bss_16
368 nop
369
370/* add offsets to GOT table */
371fixup_got:
372 set __got_start,%g4
373 set __got_end,%g3
374/*
375 * new got offset = (old GOT-PTR (read with ld) -
376 * CFG_RELOC_MONITOR_BASE(from define) ) +
377 * Destination Address (from define)
378 */
379 set CFG_RELOC_MONITOR_BASE,%g2
380 set TEXT_START, %g1
381 add %g4,%g2,%g4
382 sub %g4,%g1,%g4
383 add %g3,%g2,%g3
384 sub %g3,%g1,%g3
385 sub %g2,%g1,%g2 ! prepare register with (new base address) -
386 ! (old base address)
387got_loop:
388 ld [%g4],%l0 ! load old GOT-PTR
389 add %l0,%g2,%l0 ! increase with (new base address) -
390 ! (old base)
391 st %l0,[%g4]
392 inc 4,%g4
393 cmp %g3,%g4
394 bne got_loop
395 nop
396
397prom_relocate:
398 set __prom_start, %g2
399 set __prom_end, %g3
400 set CFG_PROM_OFFSET, %g4
401
402prom_relocate_loop:
403 ldd [%g2],%l0
404 ldd [%g2+8],%l2
405 std %l0,[%g4]
406 std %l2,[%g4+8]
407 inc 16,%g2
408 subcc %g3,%g2,%g0
409 bne prom_relocate_loop
410 inc 16,%g4
411
412/* Trap table has been moved, lets tell CPU about
413 * the new trap table address
414 */
415
416 set CFG_RELOC_MONITOR_BASE, %g2
417 wr %g0, %g2, %tbr
418
419/* call relocate*/
420 nop
421/* Call relocated init functions */
422jump:
423 set cpu_init_f2,%o1
424 set CFG_RELOC_MONITOR_BASE,%o2
425 add %o1,%o2,%o1
426 sub %o1,%g1,%o1
427 call %o1
428 clr %o0
429
430 set board_init_f,%o1
431 set CFG_RELOC_MONITOR_BASE,%o2
432 add %o1,%o2,%o1
433 sub %o1,%g1,%o1
434 call %o1
435 clr %o0
436
437dead: ta 0 ! if call returns...
438 nop
439
440/* Interrupt handler caller,
441 * reg L7: interrupt number
442 * reg L0: psr after interrupt
443 * reg L1: PC
444 * reg L2: next PC
445 * reg L3: wim
446 */
447_irq_entry:
448 SAVE_ALL
449
450 or %l0, PSR_PIL, %g2
451 wr %g2, 0x0, %psr
452 WRITE_PAUSE
453 wr %g2, PSR_ET, %psr
454 WRITE_PAUSE
455 mov %l7, %o0 ! irq level
456 set handler_irq, %o1
457 set (CFG_RELOC_MONITOR_BASE-TEXT_BASE), %o2
458 add %o1, %o2, %o1
459 call %o1
460 add %sp, SF_REGS_SZ, %o1 ! pt_regs ptr
461 or %l0, PSR_PIL, %g2 ! restore PIL after handler_irq
462 wr %g2, PSR_ET, %psr ! keep ET up
463 WRITE_PAUSE
464
465 RESTORE_ALL
466
467!Window overflow trap handler.
468 .global _window_overflow
469
470_window_overflow:
471
472 mov %wim, %l3 ! Calculate next WIM
473 mov %g1, %l7
474 srl %l3, 1, %g1
475 sll %l3, (CFG_SPARC_NWINDOWS-1) , %l4
476 or %l4, %g1, %g1
477
478 save ! Get into window to be saved.
479 mov %g1, %wim
480 nop;
481 nop;
482 nop
483 st %l0, [%sp + 0];
484 st %l1, [%sp + 4];
485 st %l2, [%sp + 8];
486 st %l3, [%sp + 12];
487 st %l4, [%sp + 16];
488 st %l5, [%sp + 20];
489 st %l6, [%sp + 24];
490 st %l7, [%sp + 28];
491 st %i0, [%sp + 32];
492 st %i1, [%sp + 36];
493 st %i2, [%sp + 40];
494 st %i3, [%sp + 44];
495 st %i4, [%sp + 48];
496 st %i5, [%sp + 52];
497 st %i6, [%sp + 56];
498 st %i7, [%sp + 60];
499 restore ! Go back to trap window.
500 mov %l7, %g1
501 jmp %l1 ! Re-execute save.
502 rett %l2
503
504/* Window underflow trap handler. */
505
506 .global _window_underflow
507
508_window_underflow:
509
510 mov %wim, %l3 ! Calculate next WIM
511 sll %l3, 1, %l4
512 srl %l3, (CFG_SPARC_NWINDOWS-1), %l5
513 or %l5, %l4, %l5
514 mov %l5, %wim
515 nop; nop; nop
516 restore ! Two restores to get into the
517 restore ! window to restore
518 ld [%sp + 0], %l0; ! Restore window from the stack
519 ld [%sp + 4], %l1;
520 ld [%sp + 8], %l2;
521 ld [%sp + 12], %l3;
522 ld [%sp + 16], %l4;
523 ld [%sp + 20], %l5;
524 ld [%sp + 24], %l6;
525 ld [%sp + 28], %l7;
526 ld [%sp + 32], %i0;
527 ld [%sp + 36], %i1;
528 ld [%sp + 40], %i2;
529 ld [%sp + 44], %i3;
530 ld [%sp + 48], %i4;
531 ld [%sp + 52], %i5;
532 ld [%sp + 56], %i6;
533 ld [%sp + 60], %i7;
534 save ! Get back to the trap window.
535 save
536 jmp %l1 ! Re-execute restore.
537 rett %l2
538
539 retl
540
541_nmi_trap:
542 nop
543 jmp %l1
544 rett %l2
545
546_hwerr:
547 ta 0
548 nop
549 nop
550 b _hwerr ! loop infinite
551 nop
552
553/* Registers to not touch at all. */
554#define t_psr l0 /* Set by caller */
555#define t_pc l1 /* Set by caller */
556#define t_npc l2 /* Set by caller */
557#define t_wim l3 /* Set by caller */
558#define t_twinmask l4 /* Set at beginning of this entry routine. */
559#define t_kstack l5 /* Set right before pt_regs frame is built */
560#define t_retpc l6 /* If you change this, change winmacro.h header file */
561#define t_systable l7 /* Never touch this, could be the syscall table ptr. */
562#define curptr g6 /* Set after pt_regs frame is built */
563
564trap_setup:
565/* build a pt_regs trap frame. */
566 sub %fp, (SF_REGS_SZ + PT_REGS_SZ), %t_kstack
567 PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2)
568
569 /* See if we are in the trap window. */
570 mov 1, %t_twinmask
571 sll %t_twinmask, %t_psr, %t_twinmask ! t_twinmask = (1 << psr)
572 andcc %t_twinmask, %t_wim, %g0
573 beq 1f ! in trap window, clean up
574 nop
575
576 /*-------------------------------------------------
577 * Spill , adjust %wim and go.
578 */
579 srl %t_wim, 0x1, %g2 ! begin computation of new %wim
580
581 set (CFG_SPARC_NWINDOWS-1), %g3 !NWINDOWS-1
582
583 sll %t_wim, %g3, %t_wim ! NWINDOWS-1
584 or %t_wim, %g2, %g2
585 and %g2, 0xff, %g2
586
587 save %g0, %g0, %g0 ! get in window to be saved
588
589 /* Set new %wim value */
590 wr %g2, 0x0, %wim
591
592 /* Save the kernel window onto the corresponding stack. */
593 RW_STORE(sp)
594
595 restore %g0, %g0, %g0
596 /*-------------------------------------------------*/
597
5981:
599 /* Trap from kernel with a window available.
600 * Just do it...
601 */
602 jmpl %t_retpc + 0x8, %g0 ! return to caller
603 mov %t_kstack, %sp ! jump onto new stack
604
605#define twin_tmp1 l4
606#define glob_tmp g4
607#define curptr g6
608ret_trap_entry:
609 wr %t_psr, 0x0, %psr ! enable nesting again, clear ET
610
611 /* Will the rett land us in the invalid window? */
612 mov 2, %g1
613 sll %g1, %t_psr, %g1
614
615 set CFG_SPARC_NWINDOWS, %g2 !NWINDOWS
616
617 srl %g1, %g2, %g2
618 or %g1, %g2, %g1
619 rd %wim, %g2
620 andcc %g2, %g1, %g0
621 be 1f ! Nope, just return from the trap
622 sll %g2, 0x1, %g1
623
624 /* We have to grab a window before returning. */
625 set (CFG_SPARC_NWINDOWS-1), %g3 !NWINDOWS-1
626
627 srl %g2, %g3, %g2
628 or %g1, %g2, %g1
629 and %g1, 0xff, %g1
630
631 wr %g1, 0x0, %wim
632
633 /* Grrr, make sure we load from the right %sp... */
634 PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1)
635
636 restore %g0, %g0, %g0
637 RW_LOAD(sp)
638 b 2f
639 save %g0, %g0, %g0
640
641 /* Reload the entire frame in case this is from a
642 * kernel system call or whatever...
643 */
6441:
645 PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1)
6462:
647 wr %t_psr, 0x0, %psr
648 nop;
649 nop;
650 nop
651
652 jmp %t_pc
653 rett %t_npc
654
655/* This is called from relocated C-code.
656 * It resets the system by jumping to _start
657 */
658_reset_reloc:
659 set start, %l0
660 call %l0
661 nop